Topic written or edited by:
Samuel S. Blumenthal, MD
Walter F. Piering, MD, FACP
Aaron Dall, MD
Kevin R. Regner, MD, MS, FASN
Ashraf El-Meanawy, MD, PhD
Jeffrey A. Wesson, MD, PhD
Hemodialysis removes wastes and excess fluid OUTSIDE your body. During a hemodialysis treatment, blood is removed from your body and pumped by a machine through a DIALYZER. The dialyzer is the semipermeable membrane that cleans your blood.
While having your treatment, you sit or lie next to a hemodialysis machine. A nurse or technician puts two needles into a vein in your forearm called an ACCESS. One needle is connected to tubing, which takes your blood out of your body to be cleaned. The blood goes back into your body through tubing attached to the other needle. There is about on cup of blood outside your body at any time. All your blood is filtered through the dialyzer several times. At the end of treatment, all the blood is back in your body.
Putting the needles into your arm can cause a little discomfort. Dialysis does not hurt, although some people do feel nauseated or dizzy during parts of the treatment. Mostly, hemodialysis is a quiet time. During treatments, most people keep busy doing things like watching TV, reading or talking.
Most people need hemodialysis three times a week. Each treatment lasts about four hours. You will be weighed before and after each treatment to make sure extra fluid is removed.
Most of the time, hemodialysis treatments are done IN-CENTER, which means they take place in a special clinic called a dialysis unit. Appointments must be scheduled in advance.
Home Hemodialysis is another way to do hemodialysis. It frees you from the dialysis center schedule, but it requires a strong commitment from a partner who must be present during all dialysis treatments. You will need to have a machine and supplies in your home.
To place an access, to get your blood, a surgeon will perform an operation to strengthen one of your veins or to put a soft tube inside your arm or thigh.
FISTULA- The surgical linking of an artery to a vein, providing access to blood vessels.
GRAFT- A tube surgically placed under the skin linking an artery to a vein.
If possible, the surgeon will attach a vein and an artery together to form a FISTULA. This is the best possible type of access. If your veins are small or weak, the surgeon inserts a GRAFT instead. This is a soft tube connected to an artery on one end and a vein on the other. Blood runs through the graft. Both a fistula and a graft are underneath the skin. The surgery needed to place an access is done in the hospital and may require an overnight stay. A permanent access can take up to a few months to heal properly.
If you need dialysis before a permanent access is in place, the doctor will create a temporary access. This is done by placing a special tube, called a catheter, in a large blood vessel under the collarbone or in the leg.
Caring for a hemodialysis access
- Check your access every day to be sure that blood is flowing through it. You can do this by placing your fingers lightly over the access to feel the pulse.
- Don’t put pressure on the access; it can cause clotting.
- Don’t sleep on the access arm.
- Don’t hold a child or anything heavy with the arm that has the access.
- Don’t wear jewelry or tight clothing over the access.
- Don’t let anyone draw blood or take your blood pressure in the arm with your access.
How will hemodialysis affect your lifestyle?
You might enjoy having four days a week when you do not have to worry about dialyzing. You will probably be able to travel if you make arrangements in advance to dialyze at another clinic (center). You can exercise and do most sports after checking with your doctor.
You will probably have to limit your intake of salt, foods rich in potassium, dairy products and fluids.
It is also very important to follow the meal plan recommended by your dietitian in order to avoid malnutrition. Poor diet can cause depression, tiredness, and a lower quality of life.
Since your body will hold on to fluids until you have your next dialysis treatment, you will gain fluid weight between sessions.
Possible complications of HD
- Blood clots
The major complication of hemodialysis is BLOOD CLOTS, clumps, of blood that block the fistula or graft. A clot must be removed or it can permanently block the access. If an access is blocked, you may need to use a temporary catheter.
During a hemodialysis session, it is normal for your body to lose fluid and salt, which can cause HYPOTENSION, low blood pressure. You may feel light-headed, sweaty or nauseated. You may also develop leg cramps or headaches during dialysis or at other times. Your doctor should be able to solve some of these problems by adjusting your dialysis. Following your diet and restricting fluids may also help.
The access may become infected. To avoid INFECTION, the skin over the access must be cleaned before the needles are put in, and needle wounds that have not healed must be protected. The signs of infection are redness at the access site, fever, and/or chills. If you have any of these signs, you should report them immediately.
In-Center Hemodialysis Advantages
- Nurses and technicians perform treatment for you
- Regular contact with other hemodialysis patients and staff
- Usually three treatments per week; four days off
- No equipment/supplies kept at home
- Medical help is available quickly in an emergency
In-Center Hemodialysis Disadvantages
- Travel to center three times a week on a fixed schedule
- Permanent access required, usually in your arm
- Insertion of two needles for each treatment
- Restricted diet/limited fluid intake
- Runs some risk of infection
- Possible discomfort like headache, nausea, leg cramps, tiredness